4K UHD Blu-ray Playback on PC Desktop is officially dead in 2021?

[usually_quiet]

Originally Posted by HDTV1080P

Stamped pressed BD-66 and BD-100 4K Blu-ray discs exist. However BDXL 100GB and 128GB blank discs are for special BD-ROM computer drives with the BDXL symbol and will not playback in a standalone 4K Blu-ray player.

The UHD Blu-ray spec doesn't cover UHD Blu-ray on any kind of burnable media, so it is true that UHD Blu-ray players are not obligated to play UHD Blu-ray on BDXL media. In fact, I can't recall seeing any UHD Blu-ray players that list BDXL as playable media for anything.

However, it is also true that some standalone UHD Blu-ray players do play copies of pressed 66GB UHD Blu-ray disc burned on 100GB BDXL as an undocumented feature, if the copy fits on the first 2 layers. I can't confirm this from personal experience but there is a years long thread about this on another forum that I belong to where plenty of others seem to be succeeding.

[Edit] I decided to look at that other forum's thread for a list of hardware UHD Blu-ray players that can play 100 GB BDXL media. Sony's UBP-X700, UBP-X800, and UBP-X800M2 will play 100 GB BDXL media if less than 66 GB is used for the data. The Panasonic DP-UB450 plays 100 GB BDXL media even when the data exceeds 66GB.